.header{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100;box-shadow:0 1px 2px rgba(23,43,92,0.03);padding:14px 0;}.header .container{display:flex;align-items:center;justify-content:space-between;}.header-left{display:flex;align-items:center;gap:40px;}.logo{font-size:25px;font-weight:700;color:var(--brand);letter-spacing:.5px;display:flex;align-items:center;gap:8px;}.logo-img{height:28px;width:auto;flex-shrink:0;}.nav{display:flex;gap:32px;}.nav a{font-size:16px;color:var(--text-3);font-weight:500;padding:6px 0;position:relative;transition:color .2s ease;}.nav a::after{content:'';position:absolute;left:0;right:0;bottom:0;height:2px;background:var(--brand);transform:scaleX(0);transform-origin:center;transition:transform .25s ease;}.nav a.active{color:var(--brand);font-weight:600;}.nav a.active::after{transform:scaleX(1);}.nav a:hover{color:var(--brand);}.nav a:hover::after{transform:scaleX(1);}.btn-login{background:var(--brand);color:#fff;padding:10px 24px;border-radius:8px;font-size:15px;font-weight:500;display:flex;align-items:center;gap:6px;cursor:pointer;border:none;transition:background .2s ease,box-shadow .2s ease;}.btn-login:hover{background:var(--brand-600);box-shadow:var(--shadow-md);}.header-actions{display:flex;align-items:center;gap:12px;flex-shrink:0;}.btn-register{background:transparent;color:var(--brand);padding:10px 24px;border-radius:8px;font-size:15px;font-weight:500;display:flex;align-items:center;gap:6px;cursor:pointer;border:1px solid var(--brand);transition:background .2s ease,box-shadow .2s ease;}.btn-register:hover{background:var(--brand-50);box-shadow:var(--shadow-sm);}.user-info{gap:10px;}.user-avatar{color:var(--brand);flex-shrink:0;}.user-name{font-size:14px;color:var(--text-2);font-weight:500;cursor:pointer;white-space:nowrap;transition:color .2s ease;}.user-name:hover{color:var(--brand);}.btn-logout{background:transparent;color:var(--text-3);padding:6px 16px;border-radius:6px;font-size:13px;font-weight:500;cursor:pointer;border:1px solid var(--border);transition:color .2s ease,border-color .2s ease,background .2s ease;white-space:nowrap;}.btn-logout:hover{color:#e53e3e;border-color:#e53e3e;background:#fef2f2;}@media(max-width:900px){.header-actions{gap:8px;}.btn-login,.btn-register{padding:8px 16px;font-size:14px;}.user-name{font-size:13px;}.btn-logout{padding:5px 12px;font-size:12px;}}